Materials Data on Ca2CrN3 by Materials Project

Abstract

Ca2CrN3 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five N3- atoms. There are a spread of Ca–N bond distances ranging from 2.36–2.77 Å. In the second Ca2+ site, Ca2+ is bonded to seven N3- atoms to form distorted CaN7 pentagonal bipyramids that share corners with four equivalent CaN7 pentagonal bipyramids, a cornercorner with one CrN4 tetrahedra, edges with three equivalent CaN7 pentagonal bipyramids, and edges with four equivalent CrN4 tetrahedra. There are a spread of Ca–N bond distances ranging from 2.42–2.80 Å. Cr5+ is bonded to four N3- atoms to form CrN4 tetrahedra that share a cornercorner with one CaN7 pentagonal bipyramid, corners with two equivalent CrN4 tetrahedra, and edges with four equivalent CaN7 pentagonal bipyramids. There are a spread of Cr–N bond distances ranging from 1.74–1.78 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a 2-coordinate geometry to two equivalent Ca2+ and two equivalent Cr5+ atoms. In the second N3- site, N3- is bonded in a 6-coordinate geometry to five Ca2+ and one Cr5+ atom. In the third N3- site, N3- is bonded to five Ca2+ and one Cr5+ atom to form a mixture of distorted edge and corner-sharing NCa5Cr octahedra. The corner-sharing octahedral tilt angles are 14°.